# OPC UA Failover Not Working **URL:** \ **Category:** Ignition\ **Created:** [September 28, 2018, 6:55am UTC](https://forum.inductiveautomation.com/t/opc-ua-failover-not-working/19874 "2018-09-28T06:55:48Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![rmdalisay](https://avatars.discourse-cdn.com/v4/letter/r/c68b51/32.png) [@rmdalisay](https://forum.inductiveautomation.com/u/rmdalisay)\ **Post date:** [September 28, 2018, 6:55am UTC](https://forum.inductiveautomation.com/t/opc-ua-failover-not-working/19874/1 "2018-09-28T06:55:48Z")
Hi all! I have 2 PC with redundant ignition OPC UA servers(the master is 10.0.8.65 and the backup is 10.0.8.71). I have a 3rd PC with ignition getting data from these redundant ignition servers via opcua. When I test stopping the master gateway, the redundancy works and all my data are still alive for the client. However on my 3rd PC, the opcua server connection becomes faulted. I have configured failover and I am expecting that when the primary opcua server becomes faulted, it will try to connect to the failover endpoint server. But when I check the logs, it keeps on trying to connect to the primary only. It does not switch on connecting to the failover. UaException: status=Bad\_ConnectionRejected, message=java.net.ConnectException: Connection refused: no further information: /10.0.8.65:4096 at org.eclipse.milo.opcua.stack.client.UaTcpStackClient.lambda$bootstrap$15(UaTcpStackClient.java:510) at io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:683) at io.netty.util.concurrent.DefaultPromise.notifyListeners0(DefaultPromise.java:604) at io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:564) at io.netty.util.concurrent.DefaultPromise.tryFailure(DefaultPromise.java:425) at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.fulfillConnectPromise(AbstractNioChannel.java:276) at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:292) at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:545) at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:485) at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:399) at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:371) at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:112) at java.lang.Thread.run(Unknown Source) Caused by: java.net.ConnectException: Connection refused: no further information: /10.0.8.65:4096 at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) at sun.nio.ch.SocketChannelImpl.finishConnect(Unknown Source) at io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:224) at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:289) … 6 more 7.9.9 (b2018081621) Oracle Corporation 1.8.0\_181 I also created a separate opcua server for the master and the backup on my 3rd pc just to ensure that I can connect to them properly and yes, I have good connection to them. ![](https://us1.discourse-cdn.com/inductiveautomation/original/2X/e/e0212af4e2601f6d04eb93ba1901f84001827fa1.png) I have seen a very similar scenario in this forum [OPC Server Connection Redundancy Settings](http://forum.inductiveautomation.com/t/opc-server-connection-redundancy-settings/18850), however, his solution did not work for me. Maybe I am missing something. But I already tried different combinations of enabling the backup and the failover but to no luck. I hope you can shed some ideas on how I can make this work. ![](https://us1.discourse-cdn.com/inductiveautomation/original/2X/1/12612d6c79ffd46d7f6e2c63c85cef397921de82.png) I am using Igition 7.9.9 Thank you so much in advance. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [September 28, 2018, 12:03pm UTC](https://forum.inductiveautomation.com/t/opc-ua-failover-not-working/19874/2 "2018-09-28T12:03:35Z")
The failover threshold of 100 may have something to do with it. ---
**Author:** ![rmdalisay](https://avatars.discourse-cdn.com/v4/letter/r/c68b51/32.png) [@rmdalisay](https://forum.inductiveautomation.com/u/rmdalisay)\ **Post date:** [September 28, 2018, 12:07pm UTC](https://forum.inductiveautomation.com/t/opc-ua-failover-not-working/19874/3 "2018-09-28T12:07:14Z")
Hi. Thanks for responding. It was originally 5. I changed it to 1 and 100 to see if this might help me resolve the issue. But no luck still. Hope you can advise me of what more I have to configure to resolve this. Am I missing something? Thanks. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [September 28, 2018, 12:11pm UTC](https://forum.inductiveautomation.com/t/opc-ua-failover-not-working/19874/4 "2018-09-28T12:11:01Z")
The threshold should go back to default. I think the endpoint failover endpoint URL might be incorrect… when you do discovery I think you get something at the end like `/iaopcua`, and that needs to be included in the setting here or it won’t match up. ---
**Author:** ![rmdalisay](https://avatars.discourse-cdn.com/v4/letter/r/c68b51/32.png) [@rmdalisay](https://forum.inductiveautomation.com/u/rmdalisay)\ **Post date:** [October 1, 2018, 2:44am UTC](https://forum.inductiveautomation.com/t/opc-ua-failover-not-working/19874/5 "2018-10-01T02:44:25Z")
Hi. I tried it also but the connection is still faulted. I tried other combinations but the connection remains faulted. I hope you can advise me on other configuration that I’m probably missing. Thanks. ![](https://us1.discourse-cdn.com/inductiveautomation/original/2X/f/f6f113c981ca18998472bc949faca821cec2e77f.png) ![](https://us1.discourse-cdn.com/inductiveautomation/original/2X/3/3751b23eb773dd1f61ec23a28e048b4726eb6b1c.png) ![](https://us1.discourse-cdn.com/inductiveautomation/original/2X/f/f03e4d5c07967d6030965d83319dce98ddfe4665.png) ![](https://us1.discourse-cdn.com/inductiveautomation/original/2X/d/d9a85582abfc3bc703d576ebed87aa82db65f16b.png) ![](https://us1.discourse-cdn.com/inductiveautomation/original/2X/8/807c0d91743f2fbbbee6f6a3970000874dbc8f5f.png) ---
**Author:** ![rs326](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/rs326/32/4500_2.png) [@rs326](https://forum.inductiveautomation.com/u/rs326)\ **Post date:** [July 31, 2019, 8:13am UTC](https://forum.inductiveautomation.com/t/opc-ua-failover-not-working/19874/6 "2019-07-31T08:13:22Z")
I am having the same issue here. I have 2 ABB PLCs with OPC UA built in. I am able to connect to them individually. I did have to add the Host over ride to get the connections going when connecting individually. However I am unable to get the fail over working. Any ideas are welcome. Thanks in advance ![ABB4](https://us1.discourse-cdn.com/inductiveautomation/original/2X/6/61c160136defbd870b16bb4b92bf4b4700325dc7.png) ![ABB3](https://us1.discourse-cdn.com/inductiveautomation/original/2X/4/4f57caeb2c8bf5dbbff9c338968c3d1ef4c8db92.png) ![ABB1](https://us1.discourse-cdn.com/inductiveautomation/original/2X/a/a4a3fc2f31671dc9fc086f9f2f3bd56ffd586bb3.png) ![ABB2](https://us1.discourse-cdn.com/inductiveautomation/original/2X/f/fc6637591d091c252428baf933cf90b6e2662b4c.png)[system\_logs\_31Jul2019-16-15-38.zip](https://us1.discourse-cdn.com/inductiveautomation/original/2X/3/331d4505221cd23a73d96f1a8aeec94f41e4cd5c.zip) (2.2 MB) ![OPC%20Server%20connections1](https://us1.discourse-cdn.com/inductiveautomation/original/2X/f/f37994715e2a3371b62acbfbc966515080f2c222.png) ---
**Author:** ![bloncar1](https://avatars.discourse-cdn.com/v4/letter/b/dfb087/32.png) [@bloncar1](https://forum.inductiveautomation.com/u/bloncar1)\ **Post date:** [October 30, 2019, 5:02pm UTC](https://forum.inductiveautomation.com/t/opc-ua-failover-not-working/19874/7 "2019-10-30T17:02:25Z")
Has this been resolved? I’m experiencing this issue with 7.9.12